<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      * {
        margin: 0;
        padding: 0;
        background-color: #333;
      }
      .line {
        position: absolute;
        top: 50%;
        width: 100%;
        height: 1px;
        transform: scaleY(0.5) translate(0, -50%);
        background-color: #fff;
      }
    </style>
  </head>
  <body>
    <div class="line"></div>
  </body>
</html>
